Machine cloth for the paper or cellulose industries

ABSTRACT

A papermaker&#39;&#39;s cloth or a cloth for similar purposes having interlacing means at both transverse edges of the cloth in the shape of loops which, when interlocked form a continuous joint in said cloth. The locking loops are formed by weaving the weft yarns in two different layers about one or two temporary threads positioned at the edge or edges of the warp, or alternatively, at the centre thereof, whereby the locking loops will be located entierly between the upper and the lower surfaces of the weave. The loops are thereafter heat treated and the temporary thread removed. The invention also concerns a method of producing said loops.

United States Patent [191 Codorniu MACHINE CLOTH FOR THE PAPER ORCELLULOSE INDUSTRIES [75] Inventor: Francisco Lorente Codorniu,

Halmstad, Sweden [73] Assignee: Nordiska Maskinfilt Aktiebolaget,

Halmstad, Sweden [22] Filed: Dec. 27, 1971 [211 APPENQE, 1 23%,

[30] Foreign Application Priority Data [58] Field of Search 139/20, 383A, 383, 425 A, 139/408410; 28/72 R; 162/D1G. l, 358, 348

[56] References Cited UNITED STATES PATENTS 1,994,280 3/1935 Hindle139/383 A 2,041,841 5/1936 Lanz..; 139/20 2,540,874 2/1951 Geddings139/383 A 2,883,734 4/1959 Draper, Jr 139/383 A 2,903,021 9/1959 Holdenet a1. 139/383 A 2,907,093 10/1959 Draper, Jr 139/383 A I 2,949,1348/1960 Hindle et a1. 139/383 A 3,030,690 4/1962 Mizell 139/383 A [1113,815,645 [4 1 June 11, 1974 3,139,117 6/1964 Koppelman et a1 139/20FOREIGN PATENTS OR APPLICATIONS 982,682 2/1965 Great Britain 139/383 A19,491 1902 Great Britain 139/409 OTHER PUBLICATlONS 325,773, 7-1970,Swedish Publ. Application (Codorniu).

Primary Examiner-James Kee Chi [57] ABSTRACT A papermakers cloth or acloth for similar purposes having interlacing means at both transverseedges of the cloth in the shape of loops which, when interlocked form acontinuous joint in said cloth. The locking loops are formed by weavingthe weft yarns in two different layers about one or two temporarythreads positioned at the edge or edges of the warp, or alternatively,at the centre thereof, whereby the locking loops will be locatedentierly between the upper and the lower surfaces of the weave. Theloops are there- I after heat treated and the temporary thread removed.

The invention also concerns a method of producing said loops.

1 Claim, 8 Drawing Figures PATENTEUJUHN '91 3.815645,

SHEET 10? 3 PATENTEDJUN 1 1 new. 3.8151345 sum 3 or 3 MACHINE CLOTH FORTHE PAPER OR CELLULOSE INDUSTRIES BACKGROUND OF THE INVENTION The normaluse of cloths for the paper and cellulose industries are in the tubular(continuous) condition. Manufacture of continuous products is in generalcarried out along two lines: as tubular (circular) fabrics or spliced(jointed) fabrics. The tubular or seamless weaving technique is appliedin most cases where the product is to be mounted in a continuouscondition. The exception thereto may be when the cloth is too long to bemanufactured according to the tubular weaving techinque or when thefield of usage is such that the tubular weaving techinque being the morecomplicated one from a manufacturing point of view, can be avoidedwithout lessening the usability of the cloth. Jointed cloths maybedivided into two groups, viz. those that permit mounting in a continuouscondition in the machine but for other reasons are not woven as tubularfabrics, and those that-necessarily must be open (unspliced) duringmounting. The former group generally permit jointing to be carried outduring the manufacture', giving a joint which in appearance and othercharacteristics on the whole agrees with the rest of the cloth. Thecloths that need be open when delivered to the site of use andsubsequently be jointed during mountingmust be provided with locks atboth cloth ends. A lock for this purpose .must, however, fulfil thefollowing demands: 1. The lock must be as durable as the rest of thecloth and as resistant against mechanical, chemical and thermaldecomposition. 2. The lock parts must be easy to join together duringmounting to ensure that the operation standstill is minimized at clothreplacements. 3. It must be easy to form the lock during the manufactureof the cloth proper. 4. In certain fields of usage there are alsodemands on minimum marking, in additionto which the lock must have thesame openness as the rest of the cloth.

The locks most commonly used are those employed for dryer cloths andcertain felt cloths, and denominated mechanical locks. These locksconstitute so called fastenerlocks similar to those used when splicingdriving-belts. The hooks 'aredriveninto the material itself or intoseparate locking straps which are then mounted on the cloth proper. Suchlocks are useful for instance for dryer cloths, although they havecertain deficiences. In other cloths, for instance those intended forcertain felts oras forming wires for the manufacture of fibreboards,locks of this kind cannot be used on account of the excessive markingthey cause. For these purposes cloths made from synthetic resin filamentyarns, usually monofilaments, are completely prevalent. In these casesthe lock is made from loops formed from the samematerial as that makingup the cloth or from a separate thread integrated with the cloth. Anexample of the former lock is disclosed in the Swedish than the jointdisclosed in the Published Application No. 322,980, primarily becausethe weaving thereof cannot be performed until the manufacturer hasreceived a particular order from the user and because the length of thecloth is limited in dependence on the width of the loom.

Although the lock in accordance with the Swedish Published ApplicationNo. 322,980 as well as the woven locks may be said to represent theprior art fulfilling all the demands enumerated above, these locks arenot quite satisfactory in some positions of use. The reason therefor isthat all loops of the kind hitherto known have possessed a maximumdimension exceeding the thickness of the cloth. Consequently, clothsincorporating such loops cannot be used for instance forKamyr-dewatering cloths, forming wires for cellulose and double wirepresses, and several others, precisely on account of the size of theloops. For these and similar positions of use tubular woven productshave so far been the only solution. The unavoidable disadvantage is thenecessity for the machine designers to install so called cantileversystems in machines of this kind. Systems of this nature naturally implyincreased machine costs, costs which are further increased as a resultof the machines becoming broader and thus demanding heavier cantileversystems.

I SUMMARY OF THE INVENTION The present invention relates to aclothhaving a lock which is suitable for use in the positions of useenumerated above andsimilar positions. The lock consists of a number ofloops formed alternatingly at the two mutually opposite transverse edgesof the cloth from one common thread which also is a part of thelongitudinal threads of the cloth (weft threads). The characterisingfeature of the invention is that the loops are positioned in theirentirety between the two planes forming the upper and the lower faces ofthe cloth. This characterising feature of the invention is obtained, inaccordance with apreferred embodiment of the invention, in that twoconsecutive weft threads at different levels in the cloth are made fromone common thread forming a locking loop in the transitional areabetween the two weft threads. 3 I

When weaving with comparatively rigid yarns, such as monofilaments,thewarp commonly forms sinuous threads in the loom, these threadscoiling or twisting about the relatively straight weft threads. As aconsequence, the warp will form the surface layers of the cloth andbecause the warp thread loops in a multileaved weave will not bepositioned in a longitudinal row of uniform loop shape the warp cannotform the locking loops in accordance with the inventionn as these willbe in a position above at least one of the surfaces of the cloth. It isthus necessary that the locking loops are formed from the weft yarnwhich, however, on account of its straightness is not very suitable forseparate splicing outside the loom. The reason herefor is that anextremely broad joint zone is required to achieve sufficient strength asthe straight threads have a low sliding resistance and may be pulled outfrom the weave fairly easily. To solve this problem the loops are, inaccordance with the invention, formed directly in a loomsuch that oneand the same thread without interruptions is used to form a series ofloops alternatively in the two edges of the cloth while the same threadsimultaneously constitutes a longitudinal thread in the finished cloth.

The present invention also concerns a method of manufacturing a clothhaving the loops as indicated above.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described morein detail in the following with reference to the accompanying drawings,in which:

FIG. 1 is a vertical transverse section taken in parallel with theextension of the warp threads in a double layer weave,

FIG. 2 is section along line IIII of FIG. 1,

FIG. 3 illustrates on an enlarged scale one marginal portion of theweave provided with the locking loops in accordance with the invention,

FIG. 4 is an end view which in the scale of FIGS. 1 and 2 illustratesthe end portions of a weave being manufactured in accordance with theteachings of the invention with locking loops at both ends of the weave,

FIG. 5 is a view similar to the one illustrated in FIG. 4 but on areduced scale and shows schematically the extension of only thosethreads of the weave which in the-position of use thereof constitute thelongitudinal threads, including the locking loops thereof,

FIG. 6 is a similar view to the one shown in FIG. 4, the locking loopsbeing, however, positioned in the upper cloth of the weave,

FIG. 7 is a similar view to the one shown in FIG. 4 but illustrates theprovision of locking loops at both edges of both the upper and the lowercloth,

FIG. 8 illustrates schematically and in a perspective view the course ofa weftthread as laid about a border thread to form the locking loops andthe extension thereof in relation to one of the warp threads.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT As illustrated in FIG. 1,the cloth comprises warp threads 1, 2, 3', 4 extending in the plane ofthe drawing, and weft threads 5, 6, 7, 8 extending normally relativelythe plane of the drawing, divided into two separate layers. The warpthreads 1, 2, 3, 4 consist of sinuous or wave-like threads which are.twisted about the comparatively straight weft threads 5, 6, 7, 8. Ifthese threads were joined in a manner similar to the one described inthe above referenced Swedish Published Application No. 322,980 theresult would be that the loops would extend partly beyond the twosurfaces 9 and 10 of the wire.

FIG. 2 illustrates the embodiment of the straight weft threads 5, 6 inthe sinuously extending warp threads 1, 2, 3, 4.

In FIG. 3 the two weft threads 5 and 6 comprise one common thread 11which thread forms the locking loop 12 at the edge of the cloth saidloop being positioned entirely between the two planes 13, 14 forming thesurface of the cloth. The locking loops are manufactured at'the sametime as the cloth itself, as is illustrated in principle in FIGS. 4 and5. The warp threads 1, 2, 3, 4 of the upper cloth and the warp threads15, I6, l7, 18 of the lower cloth are threaded through the loom comb andreed in the conventional manner. At the far end of one edge, forinstance the right one with reference to FIG. 4, is threaded a borderthread 19 of the cloth. The result thereof is that the two weft which iscoarser than the rest of the threads and preferably consists of asynthetic resin monofilament having a diameter of 2 mm. This singlethread is controlled completely individually as compared with the restof the threads of the warp. During insertion of the first weft thread 5,thread 1 is in lifted position while threads 2, 3, 4 of the upper clothand all threads 15, l6, l7, 18 of the lower cloth and border cloth 19are in lowered position. During insertion of the second weft threadborder thread 19 and threads 1, 3, 4 of the upper cloth are in liftedposition while the rest of the threads are in lowered position. Thefirst two weft threads are woven into the upper cloth. The third and thefourth weft threads pass through the lower cloth around the borderthread 19 and therefrom pass back through the lower cloth. At thetransition between the upper cloth and the lower cloth and vice versathe thread forms a so called turning fold in accordance with the commonpractice in tubular weaving. I

In accordance with another embodiment represented I in FIG. 6 the borderthread 19 has been moved to the centre of the upper cloth. The weftthread passes through one half of the upper cloth, around the borderthread and thereafter back through the lower cloth and the second halfof the upper cloth, around the border thread and back through thesamehalf of the upper cloth and the entire lower cloth. As mentioned, theborder thread extends in the centre of the upper cloth, and each edge ofthe cloth consists of saidturning fold known from the tubular weavingtechnique.

In accordance with a third embodiment illustrated in FIG. 7, twoshuttles are used. Two border threads 19" are positioned ateach selvageof the weave. One shuttle passes through the upper cloth, around theleft border thread 19 and back through the upper cloth. The secondshuttle passes through the lower cloth, around the right border thread19" and back through the lower cloth. The weave thus comprises twolocks. The cloths may be used interconnected or individually. Ifdesired, only one of the cloths may be produced, making use of oneshuttle only.

In accordance with all the embodiments referred to, the loops areexposedto a heattreatmentto set them in position before removal of theborder thread.

Contrary to the prior art types of locks mentioned in the introduction,the weft threads extend in pairs in planes which are at a right anglerelatively the surfaces threads, which together make up the same pair,correspond to one single thread only from the point of view of opennessand consequently it becomes possible to double the weft density in acloth of this kind as compared with for instance a single-layer clothwithout impairing the openness. a consequence, the number of loops islikewise doubled and thus the strength greatly improved.

The embodiments illustrated indicate one pattern only but it is evidentthat the invention is not limited thereto but embraces also other typesof weave patterns being within the scope of the appended claims.

What I claim is:

l. A flat woven double layer cloth having surfaces forming two planesand terminating in two transverse edges, having warp and weft threads,for use in the paper making and cellulose industries, particulary as acloth for dewatering and filtering and as a forming fabric for celluloseand course paper and as a press felt,

adapted for interconnection by means of a locking thread for the purposeof making said cloth endless, and said locking loops being positioned intheir entirety between the two surfaces of said cloth.

1. A flat woven double layer cloth having surfaces forming two planesand terminating in two transverse edges, having warp and weft threads,for use in the paper making and cellulose industries, particulary as acloth for dewatering and filtering and as a forming fabric for celluloseand course paper and as a press felt, said cloth having the weft threadslongitudinal in the position of use, each of said layers having firstand second planes of weft threads, locking loops formed by joiningrespective weft threads of said first plane and said second plane in thetwo transverse edges of said cloth, said locking loops of saidrespective layers being adapted for interconnection by means of alocking thread for the purpose of making said cloth endless, and saidlocking loops being positioned in their entirety between the twosurfaces of said cloth.